transaction

Documentation

Index

• Constants
• type Txn
  • func New(conn *sqlite3.SQLiteConn, id uint64, isLeader bool, dryRun bool) *Txn
  • func (t *Txn) Conn() *sqlite3.SQLiteConn
  • func (t *Txn) DryRun(v bool)
  • func (t *Txn) Frames(begin bool, frames *sqlite3.ReplicationFramesParams) error
  • func (t *Txn) ID() uint64
  • func (t *Txn) IsLeader() bool
  • func (t *Txn) IsZombie() bool
  • func (t *Txn) Resurrect(state fsm.State)
  • func (t *Txn) State() fsm.State
  • func (t *Txn) String() string
  • func (t *Txn) Undo() error
  • func (t *Txn) Zombie(state fsm.State)

Constants

const (
	Pending = fsm.State("pending") // Initial state right after creation.
	Writing = fsm.State("writing") // After the frames hook has been executed.
	Written = fsm.State("written") // After a final frames hook has been executed.
	Undone  = fsm.State("undone")  // After the undo hook has been executed.
	Doomed  = fsm.State("doomed")  // The transaction has errored.
)

Possible transaction states. Most states are associated with SQLite replication hooks that are invoked upon transitioning from one lifecycle state to the next.

Types

type Txn

type Txn struct {
	// contains filtered or unexported fields
}

Txn captures information about an active WAL write transaction that has been started on a SQLite connection configured to be in either leader or replication mode.

func New

func New(conn *sqlite3.SQLiteConn, id uint64, isLeader bool, dryRun bool) *Txn

New creates a new Txn instance.

func (*Txn) Conn

func (t *Txn) Conn() *sqlite3.SQLiteConn

Conn returns the sqlite connection that started this write transaction.

func (*Txn) DryRun

func (t *Txn) DryRun(v bool)

DryRun makes this transaction only transition between states, without actually invoking the relevant SQLite APIs. This should only be used by tests.

func (*Txn) Frames

func (t *Txn) Frames(begin bool, frames *sqlite3.ReplicationFramesParams) error

Frames writes frames to the WAL.

func (*Txn) ID

func (t *Txn) ID() uint64

ID returns the ID associated with this transaction.

func (*Txn) IsLeader

func (t *Txn) IsLeader() bool

IsLeader returns true if the underlying connection is in leader replication mode.

func (*Txn) IsZombie

func (t *Txn) IsZombie() bool

IsZombie returns true if this is a zombie transaction.

func (*Txn) Resurrect

func (t *Txn) Resurrect(state fsm.State)

Resurrect a zombie transaction, to be re-used after a leader that lost leadership was re-elected right away.

func (*Txn) State

func (t *Txn) State() fsm.State

State returns the current state of the transition.

func (*Txn) String

func (t *Txn) String() string

func (*Txn) Undo

func (t *Txn) Undo() error

Undo reverts all changes to the WAL since the start of the transaction.

func (*Txn) Zombie

func (t *Txn) Zombie(state fsm.State)

Zombie marks this transaction as zombie. It must be called only for leader transactions.

A zombie transaction is one whose leader has lost leadership while applying the associated FSM command. The transaction is left in state passed as argument.